Polyurethane over paint?

Im thinking of adding a graphic to my [thread=51500] Bait Tank[/thread]..
Im going to paint it in with Model Paint..
I will then coat the top with polyurethane..
Will polyurethane make the paint run? or is there something better I can use to cover the wood and paint?

1st pic was the original graphic I came up with to start with
2nd is my rendention on the wood hehe (I am not even close to being artist :embarassed